Document BE-531 761 discloses a construction assembly comprising a tubular rod, a sleeve and a screw. The tubular rod has an abutting surface with a hole. The sleeve has a hole and a front surface. The screw has a shank and an abutting flange. The shank extends along a longitudinal axis and includes a threaded portion. The screw is able to freely slide through the hole of the tubular rod and is able to translate without rotation around the longitudinal axis with respect to the sleeve between a retracted position and a fixing position. In the retracted position the threaded portion of the screw extends essentially within the hole of the sleeve. In the fixing position, the threaded portion of the screw protrudes from the front surface of the sleeve, the abutting flange of the screw abuts against the abutting surface of the tubular rod, and the screw is able to rotate with respect to the support around the longitudinal axis without translating along the longitudinal axis.